Brett Tabke, owner and founder of the popular WebmasterWorld forums, announced in a thread that they have built their own search engine to help forum users locate content within the forums. Brett explained that this new search engine took them about a "couple months work" and they are "very proud of it."
You can access the new search feature at webmasterworld.com/newsearch.cgi. Keep in mind, non-subscribers are allowed a maximum of 10 searches per day. According to the search page, the current size of the index is 954,078,091 bytes (909.87MB). It also is neat in that AltaVista standard boolean syntax is indeed supported.
Again, this is not WebmasterWorld competing with Google or Bing, but rather them building an internal search engine to help their users find content on WebmasterWorld. I have captured two screenshots for archival purposes.
Forum discussion at WebmasterWorld.